What are the three methods to initiate an arc in welding?

In welding, particularly in Gas Tungsten Arc Welding (GTAW), initiating an arc effectively is crucial for a successful weld. The three widely accepted methods to initiate an arc are touch start, electronic touch start, and high-frequency start.

Touch start involves manually making contact between the tungsten electrode and the workpiece, then retracting it slightly to create a spark that establishes the arc. This method is straightforward but requires careful handling to avoid contaminating the electrode.

Electronic touch start is similar to the touch method but incorporates a controlled electronic ignition process that can help stabilize the arc initiation, reducing the risk of electrode contamination and providing a more consistent start.

High-frequency start is an advanced method that uses a high-frequency AC electrical current to ionize the air gap between the tungsten electrode and the workpiece. This creates a small arc quickly without having direct contact, preventing contamination and allowing for a more rapid and clean start.

These three methods are favored for their reliability and effectiveness in creating an arc suited for precise welding applications, particularly in sensitive scenarios like GTAW.